This research replicates the study of Rush, et al. (1977) which showed Cognitive Therapy to be more effective than a tricyclic antidepressant (Imipramine) in treating outpatients with unipolar primary affective disorder. We are using the same diagnostic and inclusion criteria, the same treatment protocol, and mostly the same additional measures of patients' state and adjustment as used by Rush to permit comparisons between and within studies. Our patient population is of a lower socioeconomic status than that of Rush et al. In addition to replicating Rush's work we are adding 2 treatment groups, one receiving Cognitive therapy plus Nortriptyline and one receiving Cognitive therapy plus an active placebo. This will permit the comparison of combined treatment with either treatment alone and control for both patient and therapist expectancy effects with respect to medication. To further improve on Rush's original study, blood levels of antidepressant will be monitored to ensure the achievement of therapeutic blood levels and to assess patient compliance. All patients entered into the study will be followed up at 1 month, 6 months, and 1 year post-treatment to determine outcome according to the measures used by Rush et al.